This presentation explores the place held by Utopia in Thomas More's spiritual development. Has More been, in turn, a humanist philosopher, the author of Utopia, then a politician, and finally a saint during his imprisonment? Utopia already had strong spiritual connotations and More applied in his life what he proposed in Utopia. What makes his Utopian propositions possible? Probably the perspective of the Sadness of Christ in which are present a great number of More's favorite themes, echoing Utopia. The Dialogue of Comfort shows us the way, with Christ's Passion as a possible consequence. A personal abnegation is needed to find the freedom to act for the common good. It becomes necessary to welcome the sinner without accepting sin itself. Prudence and progress are also necessary to promote a society with more justice. This is true both in Utopia as in the relationship Christ develops with his apostles in the Sadness of Christ. The utopian ideas as a source of action for Thomas More, and the perspective of the Sadness of Christ as the condition of their realization, engender a pendulum movement which goes from the source to the achievement of a real investment for the common good. Thomas More offered his intelligence and creativity for the common good by renouncing the world, following Christ's example, and realizing the utopia. This led him to the scaffold as a consolation, experiencing the Sadness of Christ as a testimony.